rails_gemfile_entry

# File railties/lib/rails/generators/rails/plugin/plugin_generator.rb, line 317
      def rails_gemfile_entry
        if options[:skip_gemspec]
          super
        elsif rails_prerelease?
          super.dup.tap do |entry|
            entry.comment = <<~COMMENT
              Your gem is dependent on a prerelease version of Rails. Once you can lock this
              dependency down to a specific version, move it to your gemspec.
            COMMENT
          end
        end
      end